Contour roll bending machine



March 29, 1966 HAMLJN 3,242,710

CONTOUR ROLL BENDING MACHINE Filed May 22, 1963 2 Sheets-Sheet 1 GLEN HAMLIN C /Za/zZw "H. Wm

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March 29, 1966 G. HAMLIN CONTOUR ROLL BENDING MACHINE 2 Sheets-Sheet 2 Filed May 22, 1963 GLEN HAMLIN ditty.

United States Patent 3,242,710 CONTOUR ROLL BENDING MACHINE Glen Hamlin, Batavia Township, Kane County, 11]., as-

signor to Pines Engineering Co., Inc., Aurora, Ill., a corporation of Illinois Filed May 22, 1963, Ser. No. 282,512 6 Claims. (Cl. 72-156) The present invention relates to improvements in tube bending machines and is more particularly concerned with the structure and assembly of the tube bending mechanism.

More particularly, the tube bending machine disclosed herein in part only, includes novel means to effect bending of tubular stock in an' eflicient and inexpensive manner. Specifically, the structure includes a bending form of novel shape, a pressure die assembly and a novel clamp die assembly. In the embodiments illustrated, the pressure die assembly is positively driven to elfect bending of tubular stock around the bending form. The specific development of the bending form and dies is made to conform to the shape of the tubular stock, i.e.; its diameter and/or its cross sectional shape. Further, the novel clamp die assembly is located so as to insure maximum holding pressure on the tubular stock in the area of the tangent of the bending form. In one embodiment disclosed, the clamp die assembly is stationary in its relation to the bending form whereas, in the second embodiment disclosed, the clamp die assembly normally is spaced from the bending form but moves into tangential relation with said bending form during initial operation of the machine so as to clamp the tubular stock firmly between said clamp die and bending form. 7

It is, therefore, an object of the invention to provide a bending machine of novel construction.

Another object is to provide a bending machine with a novel bending form.

Still another object is to provide a bending machine with a clamp die assembly of novel construction.

Yet another object is to provide a novel longitudinally reciprocable clamp die assembly and means for reciprocating same.

Another and still further object is to provide novel means to clamp a work piece firmly against a bending form.

The structure by means of which the above noted and other objects and advantages of the invention are attained will be described in the following specification, taken in conjunction wit-h the accompanying drawings, showing preferred illustrative embodiments of the invention, in which:

FIG. 1 is a plan view of the bending end of a bending machine, showing one embodiment of the invention;

FIG. 2 is a side elevational view of the pressure die assembly;

FIG. 3 is a vertical sectional view of the bending form and clamp die assembly, taken on line 33 of FIG. 1;

FIG. 4 is a plan view of the bending end of a bending machine, showing another embodiment of the invention;

FIG. 5 is an enlarged plan view similar to FIG. 4, showing the positions assumed by the parts during use; and

FIG. 6 is a vertical sectional view taken substantially on line 66 of FIG. 5.

Refenring to the accompanying drawings which disclose exemplary embodiments of the invention, and particularly to the embodiment shown in FIGS. 1 through 3, the bending machine comprises a horizontally elongated ice housing 11 (only the right-hand end being shown) which mounts a bending form 12 that is journalled for free rotation on a vertical axis 13 on said housing. The bending form 12 comprises a disc or wheel-like structure having a tangential flat perimeter area 14, and it is suitably grooved peripherally, as at 15, to conform to the size and shape of a length of tubular stock 16 that is fed along the top of the machine and has an end portion seated in said groove.

An arm 17, journalled for rotation in a horizontal plane on the axis of the bending form, extends radially outwardly from one side of the bending machine and mounts a pressure die 18. This die has a correspondingly formed groove 19 on one face that is opposed to the bending form groove 15 so that when in the clamping position shown it firmly embraces the tubular stock 16. The pressure die 18 is movable into and out of clamping position by any suitable means such as the articulate assembly generally shown at 21, which includes linkage 22 and operating arm 23, all carried on arm 17. The machine housing 11 encloses suitable driven mechanism including a chain 24 that is operable to impart rotational movement to the arm 17 about its axis.

Insofar as described, when the arm 17 is rotated in a counter-clockwise direction, as from the full line position shown to the dot-dash line position illustrated, the tightly clamped tubular stock is carried around the bending form 12 to produce the required bend. In order to acomplish this bending with accuracy and without distortion of the remaining or trailing end of the tubular stock, it is necessary to restrain such stock in its longitudinal position rearwardly of the bending form.

Such restraining action is attained in the present instance by providing a clamp die assembly best shown at 25. This assembly is mounted firmly on a lateral plate or shelf 26 integral with the machine housing. It includes a firmly mounted jaw 27 in one end of which is journalled a roller 28. A pressure block 29 is arranged in said jaw rearwardly of the roller. Both the roller periphery and one face of the block 29 are formed With a groove correspoding to the size and shape of the tubular stock so as to embrace the same. The clamp die assembly is positioned so that the roller 28 is in alignment laterally wit-h the lateral diametrical center of the bending form so that the tubular stock is clamped firmly at the point of greatest stress, i.e., tangentially of the bending form, while the trailing portion of the tubular stock is restrained by block 29.

In the embodiment shown in FIGS. 4, 5 and 6, like numerals are used to identify corresponding parts. In this embodiment, the bending form 12a is formed with a tangential extension 31 which is opposed to the pressure die 18, and which, in this instance, normally is closely adjacent to the lateral diametrical center line x of the bending form. This positioning of the pressure die permits the formation of a more closely related series of successive bends in the tubular stock as it is advanced through the bender. However, because of the position of pressure die 18 at the start of the bending operation, it is necessary to locate the clamp die assembly 25a rearwardly of said lateral center x and, during the bending operation, to locate it tangentially therewith. To accomplish this, the clamp die assembly 25a includes a mounting jaw assembly 32 that is slidable along a longitudinal guide 33. The jaw assembly 32 carries, in this disclosure, a pair of grooved rollers 34 adapted to bear against the tubular stock. Hydraulic means, including a cylinder 35 enclosing a piston having a piston rod 36 is provided for moving the mounting jaw assembly 32. The piston rod is connected to jaw assembly 32. At the start of a bending operation, hydraulic means is actuated to advance the jaw assembly, including its rollers 34, in

the direction of the bending form 12a, as from the position shown in FIG. 4 into the position shown in FIG. 5. This advance locates the lead roller 34 tangentially with respect to the bending form so as to hold the tubular stock firmly at its point of greatest stress.

It should be understood that although a pressure block 29 and roller 28 are shown in the FIG. 1 embodiment, and a pair of rollers 34 are shown in the FIG. 4 embodiment, the number of rollers and/or blocks may be varied to suit specific requirements.

Although I have described preferred embodiments of my invention in considerable detaihit will be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details of the structures disclosed may be modified or changed Without departing from the spirit or scope of the invention. Accordingly, I do not desire to be restricted to the exact construction described.

Having described my invention, what I claim and desire to secure by Letters Patent of the United States is:

1. In a bending machine, a bending form, a pressure die to cooperate with the bending form, said prese sure die being rotatable about the axis of the bending form to bend a length of tubular stock clamped therebetween, a clamp die arranged to engage the tubular stock rearwardly of the bending form, andmeans operable to advance said clamp die in a direction longitudinally of the tubular stock into position to clamp the tubular stock between the clamp die and bending form.

2. In the bending machine recited in claim 1, in which the advancing means is hydraulically actuated.

3. In the bending machine recited in clairnl, in which the clamp die includes a pair of grooved rollers.

4. In a bending machine, a bending form, a pressure die to cooperate with the bending form, said pressure die being rotatable aboutthe axis of the bending form to bend a length of tubular stock clamped therebetween, a movable clamp die arranged to engage the tubular stock rearwardly of the bending form, guide means mounting said clampdie, and means operable to advance said clamp die longitudinally of the length of tubular stock into position to clamp the tubular stock between the clamp die and bending form.

5. Ina bending machine, a substantially circular bending form, a pressure die to cooperate with the bending form, said pressure die being rotatable about the axis of the bending form to bend a length of stock clamped between them, a clamp die arranged to engage the stock closely adjacent to but rearwa-rdly of the pressure die, and means operable to advance the said clamp die in the direction of the pressure die while said pressure die is being rotated about the bending form to clamp the stock between said clamp die and the bending form.

6. In a bending machine, a substantialy circular bending form adapted to have a length of stock fitted thereagainst, a movable clamp die arranged to engage the length of stock in advance of its engagement with the bending form, a pressure die clamping the stock to the bending form, said pressure die normally lying in the path of the clamp die and being rotatable about the axis of the bending form to bend the stock clamped between them, and means to advance the clamp die into the position normally occupied by the pressure die to clamp the stock firmly against the bending form during the bend ing operation.

References Cited by the Examiner UNITED STATES PATENTS 1,167,538 1/1916 True 72 159 1,533,443 4 11925 Miller -1 72-157 2,306,221 12/1942 Parker et a1. 72-454 3,146,818 9/1964 Schmidt 72-159 FOREIGN PATENTS 531,878 8/1955 Italy.

RICHARD J. HERBST, Primary Examiner.

CHARLES W. LANHAM, R. D. GREFE,

' Assistant Examiners. 

1. IN A BENDING MACHINE, A BENDING FORM, A PRESSURE DIE TO COOPERATE WITH THE BENDING FORM, SAID PRESSURE DIE BEING ROTATABLE ABOUT THE AXIS OF THE BENDING FORM TO BEND A LENGTH OF TUBULAR STOCK CLAMPED THEREBETWEEN, A CLAMP DIE ARRANGED TO ENGAGE THE TUBULAR STOCK REARWARDLY OF THE BENDING FORM, AND MEANS OPERABLE TO ADVANCE SAID CLAMP DIE IN A DIRECTION LONGITUDINALLY OF THE TUBULAR STOCK INTO POSITION TO CLAMP THE TUBULAR STOCK BETWEEN THE CLAMP DIE AND BENDING FORM. 